Patch-type antennas are well known for use in high frequency radio frequency (RF) applications as offering acceptable losses as compared with an isotropic antennas. Moreover, a patch offers the advantage of occupying only a limited surface area. Patch type antennas typically are dimensionally flat and include a radiator that is positioned upon a section of substrate material. The patch antenna is generally unidirectional and radiates in a plane at a right angles to the surface of the radiator. Thus, depending on the orientation of the antenna, RF radiation can be directed away from a user of a portable communications device.
One problem associated with the patch antenna is its narrow bandwidth. Typically this type of antenna will have a bandwidth of approximate 100 MHz at resonant frequency of 1.5 GHz with a voltage standing wave ratio (VSWR) of 2:1 or less. Practically speaking at such high frequencies this limits its application to situations where large changes in frequency are not encountered. Thus the need exists to provide a patch antenna that provides the advantages of low loss and directivity in a flat package that will function over a wide frequency range.